The finishing of drywalled ceilings in newly constructed or remodeled homes and offices typically employs a stippling process whereby ceilings are endowed with a textured, in lieu of a smooth, plastered finish. Application of such stippling textures can add aesthetic appeal to a room while simultaneously lessening the time required to "finish" the ceiling since minor surface imperfections are concealed by the applied texture.
During the construction of drywall type ceilings, adjacent drywall sheets abuttably contact one another, forming a discontinuous joint. Where a finished surface is desired, this joint typically is covered by the plasterer applying a plaster-based joint compound and paper tape over the seam and then smoothed out with a trowel to give the appearance of a continuous surface. After the compound has dried completely, a finishing coat of compound is applied. Where a textured ceiling finish is desired, a coat of topping compound is applied to the entire ceiling to be textured with a roller brush after the second coat of compound has been allowed to dry. Immediately upon applying the topping compound and while it is still wet, repetitive stipple patterns may be applied to the compound with a bristled brush to impart a texture to the ceiling surface. The texture pattern created by a brush is, to a large extent, determined by the length, angle and density of the brush's bristle population, as well as the viscosity of the topping compound. Stipple patterns are imparted into the wet topping compound as the contacting portion of the brush elements are drawn away from the compound.
A commonly practiced method of applying stipple patterns employs a conventional window cleaning brush attached to the end of a handle which then is dabbed into wet topping compound. While other types of brushes could be employed to apply stipple texture, such as a hatter's brush as disclosed in U.S. Pat. No. 396,812, window cleaning brushes typically are used because they are readily available to the drywall finishing trade. However, since window cleaning brushes are provided with vertically oriented and densely populated bristle arrangements, in order for them to be used as stipple brushes capable of applying consistent, generally radial stipple patterns, they must be substantially altered. Such bristle arrangement, if used in its unmodified state, would produce an inconsistent and discontinuous pattern, since it is the outer portions of the bristle lengths that would be contacting the topping compound and imparting a pattern. Even if compressed against the compound covered ceiling, an "untrained" window brush will leave an inconsistent pattern, since successive contact with the ceiling may be made with differing pressures and the bristles may spread differently each time. Consequently, any untrained brush, having generally vertically oriented bristle arrangements, would not produce a consistent, generally radial stipple pattern since such pattern requires significant lengthwise bristle contact with the wet topping compound.
In order to modify an off-the-shelf window cleaning brush to produce a generally radial stipple pattern, a substantial portion of the brush's bristles must first be removed. This thinning is required so the vertically disposed bristles can be "trained" in a radiating manner as to allow the lengthwise extent of the bristles to make parting contact with the topping compound. Bristle elements may be trained to be biased in such a radial manner by compressing a wet brush face down against a flat surface for an extended period of time. Alternately, chemically pre-trained window cleaning brushes are commercially available, such as the stipple texture brushes offered by Goldblatt Co. However, while the Goldblatt brush offers time savings which is normally spent in training a brush to lie flat, the Goldblatt brush offers no additional advantages over the standard, unmodified and untrained window cleaning brush. Only after a window brush's bristles have been adequately thinned out and trained to lie flat can the brush effectively be used to apply consistent radial stipple patterns.
However, since the modification process may vary substantially from one brush to the next, even modified and trained window brushes will produce inconsistent stipple patterns. Further, inconsistent patterns may be introduced through improper storage of a brush between uses, effectively "re-training" the brush elements in an undesirable orientation.
Inconsistent stipple patterns are not desirable and often are a source of customer complaint requiting the complete removal of the non-conforming ceiling texture in order to satisfy a customer's aesthetic tastes. Removing dried topping compound having inconsistent patterns is time consuming and generally represents an expense borne by the drywall contractor. Consequently, it is often necessary to employ the same modified window brush to finish the entire ceiling of a house to avoid visual inconsistencies that would lead to such remedial measures.
In addition to producing stipple patterns which may unintentionally vary from one modified brush to the next, the conversion of a conventional window cleaning brush into a stippling brush is inconvenient, time consuming, and prevents the brush from being used until after it has been so conditioned.
A better stipple brush would employ pre-biased brush elements which would not require substantial pre-conditioning and would contain brush elements which would produce a predetermined variety of distinctive, yet repeatable, stipple patterns. Such a pre-trained stipple brush having predetermined patterns of brush elements would save drywallers time and produce more consistent textural results. In application Ser. Nos. 07/597,885 and 07/773,020, Capoccia appreciated the need to reduce the amount of training that a craftsman has to do to a stipple brush prior to its use and disclosed a brush that could be manufactured with bristle elements at an angle from horizontal of around 20.degree.-30.degree.. Subsequently and upon further examination of manufacturing techniques, it has been discovered that, currently, there are practical limitations on the angle that automated machinery can drill into the base of the brush for providing brush receptacles. Thus, there exists a need in the art to improve the manufacturing process of such pre-trained stipple brushes.